Pulp refining apparatus



y 14, 1931- F. H. DANIELS PULP REFINING APPARATUS Filed March 31, 1928 2Sheets-Sheet l IIIIIIIII mm m 3 ww R Q Q N N M Qlull!lllllmmlmiilllilllmlu i E M Y m K m mm 1% Hum m vvi NEss fl-%%WJuly 14, DAMELS 1,814,587

PULP REFINING APPARATUS Filed March 31, 1928 2 Sheets-Sheet 2 u AINVENTOR WITNESS 4, 1 /9556- DANIELS I WXTTORNEY Patented July 14, 1931UNITED STATES PATENT OFFICE FRED H. DANIELS, F WORCESTER, MASSACHUSETTS,ASSIGNOR TO RILEY STOKER CORPORATION, OI WORCESTER, MASSACHUSETTS, ACORPORATION OF MASSACHU- SETTS PULP REFINING APPARATUS This inventionrelates to pul refining apparatus as used in the manu acture of paperand morepartieularly to a machine of this type which utilizescooperating abrall, sive stones. 1 i

It has been proposed to utilize a stationary abrasive stone and acooperating rotatable stone for the refining of paper pulp. In theseprior constructions, however, the

10 pulp and water have been introduced near the axis of the machine andpassed outwardly in the direction of centrifugal force towards theperiphery thereof. With such a constructionthe pulp passes but oncebetween the stones and if it has not been sufficiently refinedduringthis single passage, it has no further'opportunity.

It is accordingly one object of my invention to provide an apparatus ofthis eneral l0 type in which the pulpmay be cause to reolrcula'te withinthe machine and pass again and again between the stones.

Further objects of my invention are to,

provide a pulp refinin apparatus which will produce the results esiredwith a minimum. expenditure of power, which will be inexpensive tomanufacture, and which will require a small amount offloor space.

With these and other objects in view as will be apparent to thoseskilled in the art, my invent1on resides in the combination of parts setforth in the specification andcovered by the claims appended hereto.

In accordance with my invention I provide a pulp refining apparatushaving a pair of relatively rotatable abrasive stones, and I providesuitable means such as a pump, to cause the pulp to fiow inwardly fromthe periphery towards the axis of the stones against the centrifugalforce set u by the rotation. One of'the stones is pre 4 erablystationary and in order to aid in the recirculation of the pul betweenthe stones I provide grooves in the operative face of the stationarystone so that the pulp may flow along these grooves towards the centerof. the machine and a art of it be returned outwardly againto t eperiphery by the centrifugal action; of the rotating stone. 50 Referringto the drawings illustrating one embodiment of my invention and in whichlike reference numerals indicate like parts:

Fig. 1 is a vertical section through the center of my apparatus;

Fig. 2 is a cross section through the machine, the section'being takenon the line 2-2 of Fig. 1; 1

Fig. 3 is an end elevation ofthe apparatus on a smaller scale showing itconnected to a centrifugal pump;

Fig. 4 is a partialsection through the abrasive stones shown in Fig. 1,showing the shape of the grooves therein; and

a Fig. 5 is a fragmentary View similar to a portion of Fig. 1illustrating a modified form of the invention.

The embodiment of my invention illustrated in the-drawings comprises asubstantially cylindrical hollow,casing arranged with its axishorizontal. This casing is preferably divided along a horizontal planeas shown 'in Fig. 2 for convenience in manufacture and assembly and inorder to permit easy access to the interior of the apparatus.

Within the casing I provide a pair of abrasive wheels 12 and 13 ofsuitable material, such as rains of crystalline alumina or siliconcarbide bonded by vitrified ceramic materials or other'bonds, well-knownin the grinding wheel art. While both wheels may rotate I prefer thatthe wheel 12 shall be stationary, as shown in the drawings. Thisstationary stone is preferably annular in shape and may be mounted inany suit.

able manner in the casing. As illustrated, I may provide a supportingmember 15 having an inner annular flan e 16 and an outer annular flange18. The ange 18 is turned in as shown and the wheel may held in placeupon the supporting member by pouring molten sulphur or other suitablematerial between the turned-in flan e 18 and .the wheel itself. Thewheel is slightly en-.

larged in diameter at its supporting portion so that the sulphur willhold it more firmly tionary wheel 12 may be divided along a horizontalplane as illustrated in Fig. 2.

The wheel 13 is preferably annular in shape and is supported upon asuitable rotatable member, such as the vertical disk 19 which may beprovided with an inner flange 21 and an outer flange 22 corresponding tothe flanges 16 and 18 on the supporting member 15. The wheel 13 may beheld in place by the use of molten sulphur in the same way as the wheel12.

In order to drive the disk 19 it is keyed to a substantially horizontalrotatable shaft 24 which preferably extends entirely through the casing10 and is mounted in suitable ball bearings 26 and 27. .These bearingsare of a type well-known in the art, and are entirely enclosed byhousings constructed to retain the grease and keep out all grit andwater. The bearing 26 is preferably so constructed that it may .takethrust in either direction without an appreciable amount of end play.Stufiing boxes 29 and 30 are provided to prevent the leakage of waterand pulp along the shaft, and the shaft may be provided with sleeves 32and 33 of bronze or other non-corrosive material which may be replacedin case of wear. A pulley 35 may be mounted on one end of the shaft 24in order that it may be driven by a suitable source of power.

The bearings 26 and 27 are mounted for axial sliding movement in hollowcylindrical supports 37 and 38 so that the shaft may be moved lengthwiseof itself and the clearance between the abrasive Wheels thereby varied.In order to effect this adjustment conveniently a horizontal screw 40 isprovided in line with the axis of the shaft and this screw 40 has anenlarged head 41 which is rotatably mounted within the housing 43 of thebearing 26. The screw 40 passes through a stationary nut 45 and ma beturned by means of a hand wheel 46. X lock nut 47 is provided to holdthe screw in any given adjusted position.

The casing 10 is provided with an inlet opening 50 which preferablyleads into an enlarged chamber 51 in the bottom portion of the casing.There may be two of these inlet openings on opposite sides of thechamber 51 as shown in Fig. 2. By means of this construction it ispossible to connect up the machine from whichever side .is mostconvenient and the inlet not used may be closed by means of a blankflange 53. The chamber 51 serves as a receptacle for the collection ofsand or other heavy foreign material which may enter the machine withthe. pulp and water. Any accumulation of such material in the chambermay be cleaned out by first removing either of the small cover plates54:.

An outlet passage 56 is provided from the casing near the centralportion thereof and adjacent to the shaft 24:. The passage 56 may leadto a discharge pipe 57 of which theremay be one on each side of themachine, as shown in Fig. 3. The discharge the machine means must beprovided to counteract this tendency. Various devices may be used withinthe scope of my invention to produce this flow, such as a suction pumpconnected to the discharge of the machine, or a static head of water andpulp connected to the inlet of the machine; but in my preferredembodiment which I have illustrated I have utilized a pressure pump 61,which may be of the centrifugal type, and this is connected by means ofa pipe 62 to the inlet 5001. the refining apparatus. The pulp is broughtto the pump 61 from any suitable source of supply by means of a pipe 63.The rate at which the pulp flows through the machine and the pressure inthe interior of the machine may be controlled by means of gate valves 65and 66 on the discharge of the pump and the discharge of the refiningmachine respectively.

In order to assist the flow of material inwardly between the grindstones I prefer to provide a series of grooves 70 in the stationarystone 12 extending from its outer to its inner periphery. As shown inFig. 4, these grooves may be formed with one side substantiallyperpendicular to the face of the stone and with the other arranged at asuitable angle thereto. With this construction, if the rotating stone isdriven in the direction of the arrow in Fig. 4, there is a constanttendency to drag the material out of the grooves. As shown in Fig. 2these grooves 70 may each be arranged at an angle to a radial line.

If desired the rotatable stone 13 may also be provided with grooveswhich may be similar to the grooves 70 in the stationary stone. If thetwo wheels are made exactly alike, when they are assembled the two setsof grooves will cross each other as shown by the broken lines in Fig. 2and thereby pro duce a sort of a scissors action on the material. Forclearness of illustration, only three of the grooves 75 are shown inFig. 2, but it will be understood that these grooves are provided allthe way around the wheel 13 the same as on the wheel 12.

The construction shown in Fig. 5 is the same as that in Fig. 1, exceptthat a rotatix'f'g wheel is provided which has an operative surface freefrom grooves. For some purposes this construction may be preferable.

The operation of my invention will now be apparent from the abovedisclosure. The

rection indicated by the arrow 85 in Fig. 1.

The pulp and water are forced into the machine through the inlet 50 bymeans of the wheels.

centrifugal pump 61. An sand or other foreign material contained in thepulp is deposited in the chamber 51 and the ulp then flows inwardlyalong the grooves 0 1n the stationary wheel 12. If the rotating wheel isprovided with the grooves 75, as shown in Fig. 1, there will-be acontinual flow of materlal outwardly alon these grooves. If, as shown inFig. 5, t e rotating wheel is made without grooves, there will still bea flow of material outwardly along itssurface due to centrifugal force.The general course of the material as it flows through the machine isshown by the small arrows in Figs. 1 and 5; The pulp as it flows throughthe various grooves is being continually dragged laterally therefrom andrefined'by the cooperating surfaces of the abrasive After recirculatinga number of times between the wheels the refined pulp passes outwardlythrough the passage 56 to the discharge pipe of the machine.

By manipulating the valves 65 and 66 the rate of flow of the pulpthrough the machine can be controlled as desired. The pulp can be forcedrapidly through with a minimum amount of refining action by the stones,or it may be retained in the casing and recirculated again and againwhen this is considered desirable. rotating wheel and the distancebetween the stones can be varied as found best for the particular pulpat hand.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A pulp refining apparatus comprising an annular grinding wheel havinga centrally located fluid outlet, a second grinding wheel laterallyopposed to and in operative grinding relation with the other wheel, theoperative side of each wheel being plane faced and one wheel havingspaced rooves in its side face which extend from t e out- The speed ofthe connectgd with said outlet, the stones having plane faced grindingportions juxtaposed for grinding the pulp, and one having grooves in itsoperative side extending from the periphery to the inner outlet s acefor the circulation of the fluid materia means for relatively rotatingthe stones, and means for causing the material to move from the inlet tothe outlet of the casing and art of the pulp to pass freely inwardly trough the grooves while part is being ground between the stones andmoving outwardly, so that recirculation and repeated grindingof thematerial is effected.

3.- A pulp refining apparatus comprising a casing having an inlet and anoutlet in its walls'and a large free space adjacent to the inlet for thereception of foreign material,

.outer periphery of the wheel to said inner space and freely transportfluid therethrough, means for rotating one of the wheels and means tocause the pulpto move through the casing from the inlet towards theoutlet and to circulate through said grooves from the periphery towardsthe inner space while some of the material is being ground between theplane faces of the wheels.

Signed at Worcester, Massachusetts, this 28th day of March, 1928.

. FRED H. DANIELS.

er periphery to the inner outlet for trans-

